The discovery and characterization of primeval galaxies represent some of
the biggest challenges of current observational and theoretical cosmology.
This kind of studies recently entered a golden era, thanks to the
unprecedented capabilities of the Atacama Large Millimeter Array (ALMA).
Far infrared fine structure lines—[CII]158?m in particular—are
exquisite tools to search for and characterize the most remote system in
the Universe. These experiments can be combined with detailed galaxy
simulations to achieve a solid theoretical understanding.

I will present zoom-in, AMR , high-resolution (30 pc) simulations of
high-redshift (z~6) galaxies with the aim of characterizing their internal
properties and interstellar medium. Comparing our simulations with
observations allow us to draw novel and unique conclusions. In addition,
such comparison is fundamental to constrain feedback prescriptions in
simulations, which are a far cry from being fully understood.